Tribological properties of SiC-based MCD films synthesized using different carbon sources when sliding against Si3N4

摘要

Micro-crystalline diamond (MCD) films are deposited on reactive sintering SiC substrates by the bias enhanced hot filament chemical vapor deposition (BE-HFCVD) method, respectively using the methane, acetone, methanol and ethanol as the carbon source. Two sets of standard tribotests are conducted, adopting Si3N4 balls as the counterpart balls, respectively with the purpose of clarifying differences among tribological properties of different MCD films, and studying detailed effects of the carbon source C, normal load F-n and sliding velocity v based on orthogonal analyses. It is clarified that the methane-MCD film presents the lowest growth rate, the highest film quality, the highest hardness and the best adhesion, in consequence, it also performs the best tribological properties, including the lowest coefficient of friction (COF) and wear rate I-d, while the opposite is the methanol-MCD film. Under a normal load of 7 N and at a sliding velocity v of 0.4183 m/s, for the methane-MCD film, the maximum COF (MCOF) is 0.524, the average COF during the relatively steady-state regime (ACOF) is 0.144, and the I-d is about 1.016 x 10(-7) mm(3)/N m; and for the methanol-MCD film, the MCOF is 0.667, the ACOF is 0.151, and the I-d is 1.448 x 10(-7) mm(3)/N m. Moreover, the MCOF, ACOF, Id and the wear rate of the Si3N4 ball l(b) will all increase with the F-n, while the v only has significant effect on the ACOF, which shows a monotone increasing trend with the v. (C) 2016 Elsevier B.V. All rights reserved.